Judul: Protease Enzyme DPP4 Inhibitor Activity of Peptide from Hydrolyzed Etawa Crossbreed Goat Milk
Abstrak: Susu kambing merupakan sumber protein sebanding dengan susu sapi dengan kadar protein yang mencapai 4,71% sedangkan susu sapi pada kisaran 3,4%. Susu kambing lebih mudah dicerna karena ukuran misel kasein yang lebih kecil. Susu kambing yang dihidrolisis menghasilkan peptida dengan sifat bioaktif. Peptida bioaktif protein susu kambing memiliki manfaat bagi kesehatan tubuh seperti antihipertensi, antioksidan, dan antidiabetes. Sifat bioaktif antidiabetes susu kambing dapat bekerja melalui mekanisme inhibisi enzim dipeptidil peptidase 4 (DPP4). Penelitian bertujuan untuk mengetahui pengaruh hidrolisis terhadap kadar protein, aktivitas inhibisi DPP4, dan profil peptida susu kambing peranakan etawa. Susu kambing yang telah dipisahkan lemaknya dihidrolisis menggunakan enzim papain dengan aktivitas enzim spesifik 1,48 ± 0,04 U/mg pada suhu 37ºC pH 7,0. Variasi waktu hidrolisis yang digunakan adalah 0(non-hidrolisis), 1, 4, dan 24 jam. Kadar protein susu kambing mengalami penurunan dengan adanya perlakuan hidrolisis, dengan kadar protein sampel berturut sebesar 8,16; 6,74; 6,43; dan 5,96 mg/mL. Analisis aktivitas inhibisi DPP4 menunjukkan peningkatan dengan perlakuan hidrolisis, dengan aktivitas inhibisi terendah pada sampel non-hidrolisis sebesar 16,81 ± 13,83% dan aktivitas tertinggi pada hidrolisat 24 jam sebesar 96,05 ± 1,49%. Analisis profil protein menggunakan SDS-PAGE menunjukkan bahwa hidrolisis memotong protein dengan berat molekul besar seperti laktoferin (87kDa) dan Kasein (25 – 44kDa), menyisakan protein berat molekul rendah diantaranya adalah β-laktoglobulin (16 kDa) dan α-laktalbumin (10kDa)., Goat's milk is a comparable protein source to cow's milk with protein contents reaching 4,71% while cow's milk at around 3,4%. Goat milk is easier to digest due to the smaller size of casein micelles. Hydrolyzed goat milk contains peptides with bioactive properties. Bioactive peptides of goat milk protein have health benefits such as antihypertensive, antioxidant, and antidiabetic. The antidiabetic bioactive properties of goat milk can work through aimed at dipeptidyl peptidase 4 (DPP4) enzyme inhibition. This study aims to determine the effect of hydrolysis on protein content, DPP4 inhibition activity, and peptide profile of etawa crossbreed goat milk. Fat separated goat milk was hydrolyzed using papain enzyme with specific enzyme activity of 1,48 ± 0,04 U/mg at 37ºC pH 7,0. The hydrolysis time variations used were 0 (non-hydrolyzed), 1, 4, and 24 hours. Goat milk protein levels decreased with hydrolysis treatment, with protein levels of samples at 8,16; 6,74; 6,43; and 5,96 mg/mL consecutively. Analysis of DPP4 inhibition activity showed an increase with hydrolysis treatment, with the lowest inhibition activity in the non-hydrolyzed sample at 16.81 ± 13.83% and the highest activity in the 24-hour hydrolysate at 96,05 ± 1.49%. Protein profile analysis using SDS-PAGE showed that hydrolysis cut large molecular weight proteins such as lactoferrin (87kDa) and casein (25 - 44kDa), leaving low molecular weight proteins such as β-lactoglobulin (16 kDa) and α-lactalbumin (10kDa).
Keyword: antidiabetic, bioactive peptide, goat milk, papain, SDS-PAGE