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Dacres H, Weihs F, Wang J, Anderson A, Trowell SC. Bioluminescence resonance energy transfer biosensor for measuring activity of a protease secreted by Pseudomonas fluorescens growing in milk. Anal Chim Acta 2023; 1270:341401. [PMID: 37311608 DOI: 10.1016/j.aca.2023.341401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 05/18/2023] [Accepted: 05/20/2023] [Indexed: 06/15/2023]
Abstract
Bacterial proteases are sporadic contributors to milk spoilage, reducing the quality of ultra-heat treated (UHT) milk and other dairy products. Current methods for measuring bacterial protease activity in milk are insensitive and too slow to be used in routine testing in dairy processing plants. We have designed a novel bioluminescence resonance energy transfer (BRET)-based biosensor to measure the activity of proteases secreted by bacteria in milk. The BRET-based biosensor is highly selective for bacterial protease activity compared with other proteases tested, notably including plasmin, which is abundant in milk. It incorporates a novel peptide linker that is selectively cleaved by P. fluorescens AprX proteases. The peptide linker is flanked by green fluorescent protein (GFP2) at the N-terminus and a variant Renilla luciferase (RLuc2) at the C-terminus. Complete cleavage of the linker by bacterial proteases from Pseudomonas fluorescens strain 65, leads to a 95% decrease in the BRET ratio. We applied an azocasein-based calibration method to the AprX biosensor using standard international enzyme activity units. In a 10-min assay, the detection limit for AprX protease activity in buffer was equivalent to 40 pg/mL (≈0.8 pM, 22 μU/mL) and 100 pg/mL (≈2pM, 54 μU/mL) in 50% (v/v) full fat milk. The EC50 values were 1.1 ± 0.3 ng/mL (87 μU/mL) and 6.8 ± 0.2 ng/mL (540 μU/mL), respectively. The biosensor was approximately 800x more sensitive than the established FITC-Casein method in a 2-h assay, the shortest feasible time for the latter method. The protease biosensor is sensitive and fast enough to be used in production settings. It is suitable for measuring bacterial protease activity in raw and processed milk, to inform efforts to mitigate the effects of heat-stable bacterial proteases and maximise the shelf-life of dairy products.
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Affiliation(s)
- H Dacres
- CSIRO Health & Biosecurity, Food Innovation Centre, 671 Sneydes Road, Werribee, VIC, 3030, Australia
| | - F Weihs
- PPB Technology Pty Ltd, PO Box 265, Erindale Centre, ACT, 2903, Australia; CSIRO Health & Biosecurity, Canberra, ACT, 2601, Australia.
| | - J Wang
- CSIRO Health & Biosecurity, Canberra, ACT, 2601, Australia
| | - A Anderson
- CSIRO Health & Biosecurity, Canberra, ACT, 2601, Australia
| | - S C Trowell
- PPB Technology Pty Ltd, PO Box 265, Erindale Centre, ACT, 2903, Australia; CSIRO Health & Biosecurity, Canberra, ACT, 2601, Australia
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France TC, Kelly AL, Crowley SV, O’Mahony JA. Influence of processing temperature on plasmin activity and proteolysis in process streams from cold microfiltration of skim milk. Int Dairy J 2023. [DOI: 10.1016/j.idairyj.2023.105590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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Meng F, Uniacke-Lowe T, Ryan AC, Kelly AL. The composition and physico-chemical properties of human milk: A review. Trends Food Sci Technol 2021. [DOI: 10.1016/j.tifs.2021.03.040] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Zhao X, Ponchon B, Lanctôt S, Lacasse P. Invited review: Accelerating mammary gland involution after drying-off in dairy cattle. J Dairy Sci 2019; 102:6701-6717. [PMID: 31202662 DOI: 10.3168/jds.2019-16377] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 04/22/2019] [Indexed: 01/20/2023]
Abstract
Bovine mammary gland involution, as a part of the reproductive cycle in dairy cows, is a very important remodeling transformation of the mammary gland for the subsequent lactation. There is considerable incentive to accelerate mammary gland involution to improve udder health, shorten the dry period, and simplify the management process by reducing dietary changes. The complex process of mammary involution is characterized by morphological changes in the epithelial cells and mammary tissue, changes in the composition of mammary secretions, and changes in the integrity of tight junctions. Involution is facilitated by elements of the immune system and several types of proteases and is coordinated by various types of hormones. This review first describes the involution process and then argues for the need to accelerate it. Last, this review focuses on various intervention methods for accelerating involution. Our aim is to provide a comprehensive overview of bovine mammary gland involution as well as potential techniques and new opinions for dry cow management.
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Affiliation(s)
- X Zhao
- Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, QC, Canada H9X 3V9.
| | - B Ponchon
- Department of Animal Science, McGill University, Sainte-Anne-de-Bellevue, QC, Canada H9X 3V9
| | - S Lanctôt
- Sherbrooke Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada J1M 0C8
| | - P Lacasse
- Sherbrooke Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada J1M 0C8
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Demers-Mathieu V, Nielsen SD, Underwood MA, Borghese R, Dallas DC. Analysis of Milk from Mothers Who Delivered Prematurely Reveals Few Changes in Proteases and Protease Inhibitors across Gestational Age at Birth and Infant Postnatal Age. J Nutr 2017; 147:1152-1159. [PMID: 28424255 PMCID: PMC5443462 DOI: 10.3945/jn.116.244798] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Revised: 02/01/2017] [Accepted: 03/16/2017] [Indexed: 12/14/2022] Open
Abstract
Background: Peptidomics research has demonstrated that protease activity is higher in breast milk from preterm-delivering mothers than from term-delivering mothers. However, to our knowledge, the effect of the degree of prematurity and postnatal age on proteases and protease inhibitors in human milk remains unknown.Objective: We aimed to determine the change of proteases and protease inhibitors in milk from mothers who delivered prematurely across gestational age (GA) and postnatal age.Methods: Milk samples were collected from 18 mothers aged 26-40 y who delivered preterm infants and who lacked mastitis. For analysis, samples were separated into 2 groups: 9 from early GA (EGA) (24-26 wk GA)-delivering mothers and 9 from late GA (LGA) (27-32 wk GA)-delivering mothers. Within the 9 samples in each group, the collection time ranged from postnatal days 2 to 47. The activity and predicted activity of proteases in preterm milk were determined with the use of fluorometric and spectrophotometric assays and peptidomics, respectively. Protease and protease inhibitor concentrations were determined with the use of ELISA. Linear mixed models were applied to compare enzymes across GA and postnatal age.Results: Carboxypeptidase B2, kallikrein, plasmin, elastase, thrombin, and cytosol aminopeptidase were present and active in the milk of preterm-delivering mothers. Most milk protease and antiprotease concentrations did not change with GA or postnatal age. However, the concentration and activity of kallikrein, the most abundant and active protease in preterm milk, increased by 25.4 ng · mL-1 · d-1 and 0.454 μg · mL-1 · d-1 postnatally, respectively, in EGA milk samples while remaining stable in LGA milk samples.Conclusions: This research demonstrates that proteases are active in human milk and begin to degrade milk protein within the mammary gland before consumption by infants. Proteases and protease inhibitors in milk from mothers of premature infants mostly did not vary substantially across GA and postnatal age.
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Affiliation(s)
- Veronique Demers-Mathieu
- Nutrition Program, School of Biological and Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR; and
| | - Søren Drud Nielsen
- Nutrition Program, School of Biological and Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR; and
| | - Mark A Underwood
- Department of Pediatrics, University of California, Davis, Sacramento, CA
| | - Robyn Borghese
- Department of Pediatrics, University of California, Davis, Sacramento, CA
| | - David C Dallas
- Nutrition Program, School of Biological and Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR; and
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Sharma P, Oey I, Bremer P, Everett DW. Microbiological and enzymatic activity of bovine whole milk treated by pulsed electric fields. INT J DAIRY TECHNOL 2017. [DOI: 10.1111/1471-0307.12379] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Pankaj Sharma
- Department of Food Science; Gregory Building; 276 Leith Walk Dunedin 9054 New Zealand
- Riddet Institute; Massey University; Private Bag 11222 Palmerston North 4442 New Zealand
| | - Indrawati Oey
- Department of Food Science; Gregory Building; 276 Leith Walk Dunedin 9054 New Zealand
| | - Phil Bremer
- Department of Food Science; Gregory Building; 276 Leith Walk Dunedin 9054 New Zealand
| | - David W Everett
- Riddet Institute; Massey University; Private Bag 11222 Palmerston North 4442 New Zealand
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Transcellular route as the most probable explanation for the presence of plasminogen in mammal׳s milk. J Theor Biol 2016; 395:221-226. [DOI: 10.1016/j.jtbi.2016.01.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2015] [Revised: 12/06/2015] [Accepted: 01/15/2016] [Indexed: 01/24/2023]
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Boggs I, Hine B, Smolenski G, Hettinga K, Zhang L, Wheeler TT. Changes in the repertoire of bovine milk proteins during mammary involution. EUPA OPEN PROTEOMICS 2015. [DOI: 10.1016/j.euprot.2015.09.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Dallas DC, Murray NM, Gan J. Proteolytic Systems in Milk: Perspectives on the Evolutionary Function within the Mammary Gland and the Infant. J Mammary Gland Biol Neoplasia 2015; 20:133-47. [PMID: 26179272 PMCID: PMC4637187 DOI: 10.1007/s10911-015-9334-3] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Accepted: 07/02/2015] [Indexed: 12/11/2022] Open
Abstract
Milk contains elements of numerous proteolytic systems (zymogens, active proteases, protease inhibitors and protease activators) produced in part from blood, in part by mammary epithelial cells and in part by immune cell secretion. Researchers have examined milk proteases for decades, as they can cause major defects in milk quality and cheese production. Most previous research has examined these proteases with the aim to eliminate or control their actions. However, our recent peptidomics research demonstrates that these milk proteases produce specific peptides in healthy milk and continue to function within the infant's gastrointestinal tract. These findings suggest that milk proteases have an evolutionary function in aiding the infant's digestion or releasing functional peptides. In other words, the mother provides the infant with not only dietary proteins but also the means to digest them. However, proteolysis in the milk is controlled by a balance of protease inhibitors and protease activators so that only a small portion of milk proteins are digested within the mammary gland. This regulation presents a question: If proteolysis is beneficial to the infant, what benefits are gained by preventing complete proteolysis through the presence of protease inhibitors? In addition to summarizing what is known about milk proteolytic systems, we explore possible evolutionary explanations for this proteolytic balance.
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Affiliation(s)
- David C Dallas
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
- Foods for Health Institute, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA.
| | - Niamh M Murray
- Institute of Food and Health, School of Agriculture and Food Science, University College Dublin, Belfield, Dublin, Ireland
| | - Junai Gan
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
- Foods for Health Institute, University of California, Davis, One Shields Avenue, Davis, CA, 95616, USA
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The effect of health status of the udder on plasminogen activator activity of milk somatic cells in ovine milk. Small Rumin Res 2015. [DOI: 10.1016/j.smallrumres.2015.11.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Haque N, Singh M, Hossain S. PA-PG-PL System in Dairy Animals and its Significance: A Review. ACTA ACUST UNITED AC 2015. [DOI: 10.3923/ijds.2015.95.106] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Dallas DC, Guerrero A, Parker EA, Garay LA, Bhandari A, Lebrilla CB, Barile D, German JB. Peptidomic profile of milk of Holstein cows at peak lactation. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:58-65. [PMID: 24344900 PMCID: PMC4067477 DOI: 10.1021/jf4040964] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Bovine milk is known to contain naturally occurring peptides, but relatively few of their sequences have been determined. Human milk contains hundreds of endogenous peptides, and the ensemble has been documented for antimicrobial actions. Naturally occurring peptides from bovine milk were sequenced and compared with human milk peptides. Bovine milk samples from six cows in second-stage peak lactation at 78-121 days postpartum revealed 159 peptides. Most peptides (73%) were found in all six cows sampled, demonstrating the similarity of the intramammary peptide degradation across these cows. One peptide sequence, ALPIIQKLEPQIA from bovine perilipin 2, was identical to another found in human milk. Most peptides derived from β-casein, αs1-casein, and αs2-casein. No peptides derived from abundant bovine milk proteins such as lactoferrin, β-lactoglobulin, and secretory immunoglobulin A. The enzymatic cleavage analysis revealed that milk proteins were degraded by plasmin, cathepsins B and D, and elastase in all samples.
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Affiliation(s)
- David C. Dallas
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
- Foods for Health Institute, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
| | - Andres Guerrero
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
| | - Evan A. Parker
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
| | - Luis A. Garay
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
| | - Aashish Bhandari
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
| | - Carlito B. Lebrilla
- Foods for Health Institute, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
- Department of Chemistry, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
| | - Daniela Barile
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
- Foods for Health Institute, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
| | - J. Bruce German
- Department of Food Science and Technology, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
- Foods for Health Institute, University of California, Davis, One Shields Avenue, Davis, CA, 95616, United States
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Dallas DC, Guerrero A, Khaldi N, Castillo PA, Martin WF, Smilowitz JT, Bevins CL, Barile D, German JB, Lebrilla CB. Extensive in vivo human milk peptidomics reveals specific proteolysis yielding protective antimicrobial peptides. J Proteome Res 2013; 12:2295-304. [PMID: 23586814 DOI: 10.1021/pr400212z] [Citation(s) in RCA: 121] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Milk is traditionally considered an ideal source of the basic elemental nutrients required by infants. More detailed examination is revealing that milk represents a more functional ensemble of components with benefits to both infants and mothers. A comprehensive peptidomics method was developed and used to analyze human milk yielding an extensive array of protein products present in the fluid. Over 300 milk peptides were identified originating from major and many minor protein components of milk. As expected, the majority of peptides derived from β-casein, however no peptide fragments from the major milk proteins lactoferrin, α-lactalbumin, and secretory immunoglobulin A were identified. Proteolysis in the mammary gland is selective-released peptides were drawn only from specific proteins and typically from only select parts of the parent sequence. A large number of the peptides showed significant sequence overlap with peptides with known antimicrobial or immunomodulatory functions. Antibacterial assays showed the milk peptide mixtures inhibited the growth of Escherichia coli and Staphylococcus aureus . The predigestion of milk proteins and the consequent release of antibacterial peptides may provide a selective advantage through evolution by protecting both the mother's mammary gland and her nursing offspring from infection.
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Affiliation(s)
- David C Dallas
- Department of Food Science and Technology, University of California at Davis, One Shields Avenue, Davis, California 95616, USA
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Tissue-type plasminogen activator and plasminogen embedded in casein rule its degradation under physiological situations: manipulation with casein hydrolysate. J DAIRY RES 2013; 80:227-32. [DOI: 10.1017/s0022029913000010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The aims of this study were to test the assumption that tissue-type plasminogen activator (t-PA) and plasminogen (PG) are closely associated with the casein micelle and form a functional complex that rules casein degradation. This assumption was essentially verified for bovine milk under conditions wherein the plasmin system was activated by treatment with casein hydrolysate. It was also shown that urokinase-type PA (u-PA), the second type of plasminogen activator present in milk, was not involved in casein degradation. In agreement with previous studies, we show that treatment with casein hydrolysate precipitously reduced mammary secretion, disrupted the tight junction integrity (increase in Na+ and decrease in K+ concentrations), induced hydrolysis of casein, and activated various elements of the innate and acquired immune system. In the present study, we have identified t-PA as the principal PA, which is responsible for the conversion of PG to plasmin. It was found that t-PA and plasminogen are present in freshly secreted milk (less than 10 min from its secretion), suggesting that they are secreted as a complex by the mammary gland epithelial cells. Further research is needed to provide the direct evidence to verify this concept.
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Díaz-Martín V, Manzano-Román R, Oleaga A, Encinas-Grandes A, Pérez-Sánchez R. Cloning and characterization of a plasminogen-binding enolase from the saliva of the argasid tick Ornithodoros moubata. Vet Parasitol 2012; 191:301-14. [PMID: 23089148 DOI: 10.1016/j.vetpar.2012.09.019] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2012] [Revised: 09/07/2012] [Accepted: 09/14/2012] [Indexed: 01/09/2023]
Abstract
Significant amounts of enolase have recently been found in the saliva of the argasid tick Ornithodoros moubata, raising the question as to what the function of enolase in the tick-host interface is. Enolase is a multifunctional glycolytic enzyme known to act as a plasminogen receptor on cellular surfaces, promoting fibrinolysis and extracellular matrix degradation. Fibrinolysis could be important for ticks to dissolve clots that might be formed during feeding as well as to prevent clotting of the ingested blood meal in the tick midgut. Additionally, enolase-mediated extracellular matrix degradation could contribute to the tick feeding lesion. Moreover, previous observations suggested an additional antihaemostatic role for O. moubata enolase as a P-selectin antagonist ligand. Accordingly, the aim of the present study was to investigate the potential role of the O. moubata salivary enolase as a plasminogen receptor and P-selectin ligand, and to evaluate its potential as an antigen target for anti-O. moubata vaccines. The study included the cloning, sequencing and recombinant production of the O. moubata enolase, plasminogen binding and activation assays, P-selectin binding assays, animal immunization trials, and RNAi knockdown of the enolase gene. Here we confirmed that enolase is secreted to the saliva of the tick and provide convincing evidence for a role of this salivary enolase as a plasminogen receptor, most likely stimulating host fibrinolysis and maintaining blood fluidity during tick feeding. The RNAi experiments and immunization trials indicated that enolase could be also involved in the regulation of tick reproduction, suggesting new potential control strategies. Finally, the P-selectin binding experiments demonstrated that this enolase is not a P-selectin ligand.
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Affiliation(s)
- Verónica Díaz-Martín
- Parasitología Animal, Instituto de Recursos Naturales y Agrobiología de Salamanca, Cordel de Merinas, 40-52, 37008, Salamanca, Spain
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Wang L, Mauer LJ. Effect of Heat on the Distribution of Fluorescently Labeled Plasminogen and Plasminogen Activators in Bovine Skim Milk. J Food Sci 2008; 73:C185-90. [DOI: 10.1111/j.1750-3841.2007.00666.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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17
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Effects of heat and β-lactoglobulin on distribution of fluorescently labeled tissue- and urokinase-type plasminogen activators in a model milk system. Int Dairy J 2007. [DOI: 10.1016/j.idairyj.2006.06.025] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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De Noni I, Pellegrino L, Cattaneo S, Resmini P. HPLC of proteose peptones for evaluating ageing of packaged pasteurized milk. Int Dairy J 2007. [DOI: 10.1016/j.idairyj.2005.12.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Weng MH, Chang CJ, Chen WY, Chou WK, Peh HC, Huang MC, Chen MT, Nagahata H. Contribution of somatic cell-associated activation of plasminogen to caseinolysis within the goat mammary gland. J Dairy Sci 2006; 89:2025-37. [PMID: 16702266 DOI: 10.3168/jds.s0022-0302(06)72270-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Functional regression of the mammary gland is partly reflected by proteolysis of milk protein and tissue protein. The involvement of the plasminogen activation system in degradation of milk protein and mammary tissue damage has been demonstrated under inflammatory conditions. In this study, mammary secretion from 23 dairy goats primarily grouped as lactation (milking twice daily) or involution (milking once daily or less) was used to determine the ratio of gravity-precipitated casein to total milk protein (casein ratio) as an index of caseinolysis, and activities of components of plasminogen activation system as well as their expressions on somatic cells. Based on the casein ratio, lactation goats were subcategorized as very active (71.8 +/- 1.0%) or less active (29.9 +/- 1.0%) in mammary function; involution goats were subcategorized as gradual (21.7 +/- 1.0%) or acute (5.9 +/- 0.2%) involution. This result suggests that caseinolysis occurred during regular lactation as well as during involution. On the other hand, activities of components of the plasminogen activation system in mammary secretion were increased along with the decreasing casein ratio, in contrast to the similar activities of their counterparts in circulation throughout various mammary statuses. Correlation analysis between casein ratio and activities of plasminogen activation system of goat milk indicated a significant negative relationship for plasmin (r = -0.64), plasminogen (r = -0.69), and urokinase-type plasminogen activator (uPA; r = -0.78) during involution but not during lactation. As for the cellular components of plasminogen activation system, there was an increase in immunoreactivity on somatic cells toward both monoclonal antibodies of human uPA and human uPA receptor under involution conditions suggesting their upregulation relative to lactation condition. Collectively, these results suggest that plasminogen activation system within the mammary gland differentially contribute to milk caseinolysis along the various stages of goat lactation. Meanwhile, a somatic cell-mediated local elevation of plasmin activity may be committed to extensive caseinolysis during involution.
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Affiliation(s)
- M H Weng
- Department of Animal Science, National Chung Hsing University, Taichung, Taiwan, Republic of China, 402
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Benfeldt C. Ultrafiltration of cheese milk: Effect on plasmin activity and proteolysis during cheese ripening. Int Dairy J 2006. [DOI: 10.1016/j.idairyj.2005.10.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Silanikove N, Merin U, Leitner G. Physiological role of indigenous milk enzymes: An overview of an evolving picture. Int Dairy J 2006. [DOI: 10.1016/j.idairyj.2005.08.015] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Crudden A, Afoufa-Bastien D, Fox PF, Brisson G, Kelly AL. Effect of hydrolysis of casein by plasmin on the heat stability of milk. Int Dairy J 2005. [DOI: 10.1016/j.idairyj.2004.11.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Mehrzad J, Desrosiers C, Lauzon K, Robitaille G, Zhao X, Lacasse P. Proteases Involved in Mammary Tissue Damage During Endotoxin-Induced Mastitis in Dairy Cows. J Dairy Sci 2005; 88:211-22. [PMID: 15591384 DOI: 10.3168/jds.s0022-0302(05)72679-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
During and after diapedesis, milk polymorphonu-clear neutrophils (PMN) release many proteases that have the potential of degrading extracellular matrix proteins and milk proteins. However, the kinetics of milk proteolysis during inflammation and the underlying mechanisms are poorly defined. The enzymes involved in bovine mammary tissue destruction were investigated in this study using an endotoxin-induced mastitis model. Using zymography techniques, the proteolytic activity of milk and mammary tissue during mastitis was examined. Mastitic milk produced 6 caseolysis bands, 4 of which differed from the ones produced by plasmin. Peak proteolytic activity, bovine serum albumin contents, and mammary tissue damage occurred between 6 and 12 h postchallenge. Mastitic milk proteases hydrolyzed casein, gelatin, collagen, hemoglobin, mammary gland membrane proteins, and lactoferrin. These results confirm that mastitic milk proteases have a broad spectrum of activity. The hydrolytic activity of mastitic milk was partially inhibited by aprotinin, EDTA, 1,10-phenanthroline, leupeptin, and pefabloc. When cocultured with normal mammary tissue, mastitic milk, but not normal milk, caused mammary tissue degradation. In situ zymography of mammary gland showed increased proteolytic activity in mastitic tissue compared with normal tissue. The similarity of zymograms of mastitic milk, blood PMN, milk somatic cells, and PMN strongly suggests that proteases in mastitic milk mainly originate from milk PMN. These results suggest that proteases released by PMN are actively involved in udder tissue damage during mastitis.
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Affiliation(s)
- J Mehrzad
- Dairy and Swine Research and Development Centre, Agriculture and Agri-Food Canada, Lennoxville, QC, J1M 1Z3, Canada
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Bianchi L, Bolla A, Budelli E, Caroli A, Casoli C, Pauselli M, Duranti E. Effect of Udder Health Status and Lactation Phase on the Characteristics of Sardinian Ewe Milk. J Dairy Sci 2004; 87:2401-8. [PMID: 15328261 DOI: 10.3168/jds.s0022-0302(04)73362-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mammary involution and inflammation are known to negatively affect milk quality. A trial was carried out to elucidate the mechanism by which udder health status and lactational phase determine compositional modifications in ovine milk. A total of 60 individual milk samples was collected from a group of 20 pluriparous Sardinian ewes from mid to late lactation. Each sample was assessed for its chemical characteristics, quantitative distribution of casein fractions, lactodynamographic characteristics, and enzymatic activity. Udders were classed as healthy, doubtful, or infected on the basis of repeated somatic cell counts, and samples were grouped in 3 classes of days in milk. Results indicated that both udder inflammation and mammary involution can increase plasmin (PL) activity (15.6 vs. 18.4 U/mL in healthy vs. infected udders; 14.0 vs. 20.2 U/mL in phase 1 vs. 3), which is responsible for an evident protein breakdown in milk. Significant differences between groups were observed for several characteristics. With regard to udder heath status, casein index was lower in the infected vs. healthy udders (74.8 vs. 76.6%), and beta(tot)-casein showed a similar trend (43.9 vs. 46.6%). As a consequence of protein degradation, gamma-casein (5.78 vs. 2.82%) and proteolysis index (7.60 vs. 3.82) increased in the infected group with respect to the healthy group. Udder health status also affected milk technological traits. Udder inflammation resulted in longer clotting time (20.7 vs. 16.5 min for infected vs. healthy, respectively) and in poorer curd firmness (35.6 vs. 47.6 mm for infected vs. healthy, respectively). Frequency of samples reactive to rennet was 100, 93, and 67%, respectively, for healthy, doubtful, and infected groups. With regard to lactational phase, a decrease in alpha(s1)-casein (39.13 vs. 29.36%) and beta(1)-casein (23.41 vs. 19.36%) occurred during phase 1 vs. 3, whereas kappa + alpha(s2)-casein increased (12.30 vs. 21.56%, phase 1 vs. 3). Correlation coefficients confirmed the role of PL in protein degradation. It was concluded that PL activity was strongly affected by both lactational phase and udder health status and, in turn, could be an important agent enhancing milk quality detriment.
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Affiliation(s)
- L Bianchi
- Dipartimento di Scienze Zootecniche, Università degli Studi di Perugia, 06121 Perugia, Italy
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Nielsen SS. Plasmin system and microbial proteases in milk: characteristics, roles, and relationship. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2002; 50:6628-6634. [PMID: 12381162 DOI: 10.1021/jf0201881] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Proteolysis of milk proteins can be attributed to both native proteases and the proteases produced by psychrotrophic bacteria during storage of fresh raw milk. These proteases cause beneficial or detrimental changes, depending on the specific milk product. Plasmin, the major native protease in milk, is important for cheese ripening. Milk storage and cheese-making conditions can affect the level of plasmin in the casein and whey fractions of milk. A microbial protease from a psychrotrophic microorganism can indirectly increase plasmin levels in the casein curd. This relationship between the plasmin system and microbial proteases in milk provides a means to control levels of plasmin to benefit the quality of dairy products. This paper is a short review of both the plasmin system and microbial proteases, focusing on their characteristics and relationship and how the quality of dairy products is affected by their proteolysis of milk proteins.
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Affiliation(s)
- S Suzanne Nielsen
- Department of Food Science, Purdue University, West Lafayette, Indiana 47907-1160, USA
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Moussaoui F, Michelutti I, Le Roux Y, Laurent F. Mechanisms involved in milk endogenous proteolysis induced by a lipopolysaccharide experimental mastitis. J Dairy Sci 2002; 85:2562-70. [PMID: 12416808 DOI: 10.3168/jds.s0022-0302(02)74339-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Experimental mastitis has been induced by the lipopolysaccharide (LPS) of Escherichia coli on six dairy cows in order to study the mechanisms involved in milk endogenous proteolysis during the inflammatory process. Variations in somatic cell count (SCC), plasmin activity, and total casein (CN) content were measured, and proteose-peptone content and the percentage of pH 4.6 insoluble peptides including gamma-CN have been considered as indicators of endogenous proteolysis. Furthermore, polymorphonuclear neutrophils (PMN) maturity has been evaluated by optical microscopy, and proteolysis by PMN proteinases has been studied at neutral and acidic pH in order to establish a link between caseinolysis, proteinase class, and PMN maturation. Two peaks of proteose-peptones content have been noticed for the six cows. First peak could be explained by both plasmin activity and SCC, while second peak was concomitant with a low plasmin activity but a SCC remaining high. The second peak of proteose-peptones content confirmed the role of cellular proteases in milk caseinolysis. Casein breakdown by cellular proteases was confirmed by SDS-PAGE electrophoresis, and a link between neutral proteinases activity and immature PMN recruitment was shown. Acidic proteinases activity was effective with mature PMN and during the recovery phase.
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Affiliation(s)
- F Moussaoui
- Unité sous contrat avec l'Institut National de la Recherche Agronomique, Ecole Nationale Supérieure d'Agronomie et des Industries Alimentaires, Vandoeuvre-lés-Nancy, France.
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Athie F, Bachman KC, Head HH, Hayen MJ, Wilcox CJ. Milk plasmin during bovine mammary involution that has been accelerated by estrogen. J Dairy Sci 1997; 80:1561-8. [PMID: 9276794 DOI: 10.3168/jds.s0022-0302(97)76086-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The purpose of this study was to evaluate whether the plasminogen and plasmin system within bovine mammary secretions was influenced by an estrogen treatment that was used to accelerate mammary tissue involution. Holstein cows were injected with 4 ml of ethanol excipient (n = 21) or 15 mg of estradiol-17 beta (n = 23) on each of the 4 d that preceded final milk removal. Dates of final milk removal (d 0) were designated as 60 d prior to expected dates of calving. Each mammary quarter was sampled once to collect secretions that corresponded to d 0, 3, 11, and 25 or d 1, 7, 18, and 30 of the dry period. Concentrations of plasminogen, plasmin, and somatic cells in secretions increased earlier for treated cows than for control cows. The ratio of plasminogen to plasmin in secretions decreased earlier for treated cows than for control cows. These responses support the suggestion that the plasminogen and plasmin system is involved in the involution of bovine mammary tissue. Estrogen treatment increased the activation of plasminogen, which was evidenced by a precipitous decrease in the ratio of plasminogen to plasmin that occurred as concentrations of plasminogen and plasmin increased. The activation of plasminogen likely contributed to the increased rate of mammary tissue involution that was effected by exogenous estrogen. Endogenous estrogen secreted by the developing fetal and placental unit might mediate, in part, the gradual involution that occurs during lactation.
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Affiliation(s)
- F Athie
- Department of Dairy and Poultry Sciences, University of Florida, Gainesville 32611, USA
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Precetti AS, Oria MP, Nielsen SS. Presence in bovine milk of two protease inhibitors of the plasmin system. J Dairy Sci 1997; 80:1490-6. [PMID: 9276788 DOI: 10.3168/jds.s0022-0302(97)76077-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Proteolysis, caused by the serine proteinase plasmin (EC 3.4.21.7) that is present in milk, influences the quality of dairy products. Within the plasmin system, activators and inhibitors control plasmin activity. This study investigated the presence in bovine milk of two serine proteinase inhibitors of the plasmin system, alpha(2)-antiplasmin and plasminogen activator inhibitor-1, and an isolation procedure used for partial purification of them from milk. Two colorimetric assays were used to detect either plasmin inhibitor activity or plasminogen activator inhibitor activity. Two inhibitors were partially purified from milk using a combination of ammonium sulfate fractionation and concanavalin A affinity chromatography. Plasminogen activator inhibitor-1 and alpha(2)-antiplasmin antigens, which were associated with the inhibitory activities from bovine milk, were visualized by Western blot using commercial polyclonal antibodies raised against the corresponding human inhibitors. Both inhibitors were present in milk as several forms, possibly from the formation of complexes with other milk proteins. The predominant forms of the inhibitors in milk exhibited an approximate molecular mass of 60 kDa for alpha(2)-antiplasmin and 55 kDa for plasminogen activator inhibitor-1.
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Affiliation(s)
- A S Precetti
- Department of Food Science, Purdue University, West Lafayette, IN 47907, USA
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Heegaard CW, Larsen LB, Rasmussen LK, Højberg KE, Petersen TE, Andreasen PA. Plasminogen activation system in human milk. J Pediatr Gastroenterol Nutr 1997; 25:159-66. [PMID: 9252902 DOI: 10.1097/00005176-199708000-00006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
BACKGROUND Plasmin is the major endogenous protease present in milk. The level of plasmin activity is controlled by the availability of the precursor plasminogen and by the levels of plasminogen activators and inhibitors. Recently, a differential distribution of tissue-type plasminogen activator (t-PA) and urokinase-type plasminogen activator (u-PA) has been demonstrated in bovine milk. To assess whether this distribution pattern is a general feature, the occurrence of components of the plasminogen activation system in different fractions of human milk was investigated. METHODS Milk samples were separated into the following fractions; milk fat, skim milk, and milk cells by centrifugation. The different fractions were detected for the presence of plasminogen and plasminogen activators by immunoblotting and zymography. The distribution of t-PA and u-PA was investigated by ligand binding analysis. t-PA-catalyzed plasminogen activation was examined by a coupled chromogenic assay. RESULTS A differential distribution of plasminogen, t-PA, and u-PA was found. Casein micelles were found to exhibit t-PA and plasminogen binding activity, whereas the u-PA receptor was identified as the u-PA binding component in the cell fraction. Furthermore, human casein enhanced t-PA-catalyzed plasminogen activation, comparable to the enhancing effect obtained with fibrinogen fragments. CONCLUSION The finding of a differential distribution of u-PA and t-PA in milk suggests that the two activators may have different physiological functions, which involve protection against invading microorganisms and maintenance of patency and fluidity in the ducts of mammary gland, respectively.
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Affiliation(s)
- C W Heegaard
- Department of Molecular and Structural Biology, University of Aarhus, Denmark
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Heegaard C, Andreasen P, Petersen T, Rasmussen L. Binding of plasminogen and tissue-type plasminogen activator to dimeric αs2-casein accelerates plasmin generation. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s0268-9499(97)80006-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Zavizion B, Heegard CW, White J, Cheli F, Politis I. Synthesis of plasminogen activator inhibitor 1 by bovine mammary epithelial and myoepithelial cell lines. J DAIRY RES 1996; 63:451-8. [PMID: 8864936 DOI: 10.1017/s0022029900031952] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Conversion of plasminogen to plasmin provides an important source of proteolytic activity in the bovine mammary gland. Plasminogen activator inhibitor 1 (PAI-1) plays a key role in limiting plasminogen activation. The PAI-1 biosynthetic capabilities of various bovine mammary cells were determined. The immortalized epithelial cell lines MAC-T and BME-UV and the myoepithelial cell line BMM-UV were used as model systems. Northern blot analysis indicated that both epithelial and myoepithelial cells contained PAI-1 mRNA. Bovine PAI-1 was encoded by a single mRNA species approximately 3.0 kb long. BME-UV cells contained 2.0-fold (P < 0.01) the PAI-1 mRNA of MAC-T or BMM-UV cells. Reverse zymography indicated that both epithelial and myoepithelial cells synthesized PAI-1 protein with a molecular mass of approximately 50 kDa.
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Affiliation(s)
- B Zavizion
- Department of Animal and Food Sciences, University of Vermont, Burlington 05404, USA
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Conformational changes in plasminogen, their effect on activation, and the agents that modulate activation rates — a review. ACTA ACUST UNITED AC 1996. [DOI: 10.1016/s0268-9499(96)80082-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Heegaard CW, Simonsen AC, Oka K, Kjøller L, Christensen A, Madsen B, Ellgaard L, Chan L, Andreasen PA. Very low density lipoprotein receptor binds and mediates endocytosis of urokinase-type plasminogen activator-type-1 plasminogen activator inhibitor complex. J Biol Chem 1995; 270:20855-61. [PMID: 7657671 DOI: 10.1074/jbc.270.35.20855] [Citation(s) in RCA: 91] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Very low density lipoprotein receptor (VLDL-R) was found to be expressed in bovine mammary gland and the human breast carcinoma cell line MCF-7 as an M(r) 105,000 variant, and in Chinese hamster ovary (CHO) cells transfected with human VLDL-R cDNA as an M(r) 130,000 variant. The receptor was purified by ligand affinity chromatography with immobilized M(r) 40,000 receptor-associated protein (RAP). The purified receptor was found to bind urokinase-type plasminogen activator-type-1 plasminogen activator inhibitor complex (u-PA.PAI-1), while there was no or very weak binding of active site blocked u-PA (DFP-u-PA), PAI-1 or u-PA-type-2 plasminogen activator inhibitor complex. The binding of u-PA.PAI-1 was blocked by RAP. The transfected CHO cells had an efficient, RAP-sensitive endocytosis of u-PA.PAI-1, severalfold higher than non-transfected parental CHO cells. u-PA.PAI-1 endocytosis was partially inhibited by DFP-u-PA, which blocks binding of the complex to the u-PA receptor. RAP and DFP-u-PA sensitive u-PA.PAI-1 endocytosis was also observed in MCF-7 cells, which were without detectable levels of other RAP-binding endocytosis receptors. These results show that VLDL-R represents a novel endocytosis mechanism for u-PA receptor-bound u-PA.PAI-1.
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Affiliation(s)
- C W Heegaard
- Department of Molecular Biology, University of Aarhus, Denmark
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Benfeldt C, Larsen LB, Rasmussen JT, Andreasen PA, Petersen TE. Isolation and characterization of plasminogen and plasmin from bovine milk. Int Dairy J 1995. [DOI: 10.1016/0958-6946(94)00035-n] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Ravn P, Berglund L, Petersen TE. Cloning and characterization of the bovine plasminogen activators uPA and tPA. Int Dairy J 1995. [DOI: 10.1016/0958-6946(94)00034-m] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Simonsen AC, Heegaard CW, Rasmussen LK, Ellgaard L, Kjøller L, Christensen A, Etzerodt M, Andreasen PA. Very low density lipoprotein receptor from mammary gland and mammary epithelial cell lines binds and mediates endocytosis of M(r) 40,000 receptor associated protein. FEBS Lett 1994; 354:279-83. [PMID: 7957939 DOI: 10.1016/0014-5793(94)01138-9] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We here report that the M(r) 40,000 receptor associated protein (RAP), previously found to bind to alpha 2-macroglobulin receptor/low density lipoprotein receptor related protein (alpha 2MR/LRP) and glycoprotein 330 (gp330), binds to an M(r) 105,000 membrane protein from bovine mammary gland, human mamma tumors and mammary epithelial cell lines. We have purified this protein from bovine and human sources. N-terminal amino acid sequencing and immunoblotting analyses showed that the protein was identical or closely related to very low density lipoprotein receptor (VLDL-R). Experiments with the human mamma carcinoma cell line MCF-7 showed that this receptor was able to mediate an efficient endocytosis of RAP. These novel findings strongly suggest that RAP functions as a modulator of ligand binding to VLDL-R, similarly to alpha 2MR/LRP and gp330.
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Affiliation(s)
- A C Simonsen
- Department of Molecular Biology, University of Aarhus, Denmark
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